For ages, people have used metal to make artefacts and structures. There are a number of methods to form metal, one of them including metal casting. Usually, a molten metal is poured into a mould to make the product. A common method that can be done in the home is called lost wax casting. Any metal can be cast, from aluminium to bronze. Lost wax moulds are made by making a wax sculpture of what your product will look like, casting investment (a plaster-like material) around the sculpture, melting out the wax, and then pouring or injecting metal into it.
Determine what you want your final product to look like and mould it out of wax using an X-Acto knife.
Melt the tip of a wax sprue and connect it to the bottom of the wax sculpture. Later, after the wax is melted from the investment casting, the sprue will leave a channel for the metal to flow through.
Cut a chunk of mouldable wax and stick it to the rubber base. Then connect the wax sprue on the sculpture to the chunk of mouldable wax. The rubber base needs to have about the same width as the can.
Remove the bottom of a can with the safe cut can opener which will cut the bead of the can and will not leave a sharp edge.
Take the can and place it over the sculpture and onto the rubber base. Make sure to get a good seal by placing masking tape around the edge of the can and the rubber base.
Measure the investment material and water according to the manufacturer specifications and mix.
Pour the investment into the can and make sure to completely cover the sculpture. Let the investment dry for the time designated by the manufacturer. Remove the rubber base after it dries.
Place the investment mould into the furnace at 660 degrees Celsius, the melting temperature of aluminium. If the mould is the same temperature as the molten aluminium, then the aluminium will flow through it without cooling and stopping. Make sure the wax end is facing down so that it pours out and leave the investment in the oven overnight.
Melt the aluminium metal in a crucible with an oxyacetylene torch.
Remove the mould from the furnace, and using metal tongs, pour the aluminium into the hole where the wax once was. Allow the metal to cool for several hours to achieve the greatest strength.
Put the mould into a bucket of water and swish it around. The investment will fall off of the final product, leaving an aluminium casting.
Make moulds using different waxes for different properties and results. Try casting with different plasters to achieve different surface finishes.
Always wear proper clothing, materials and chemicals can get on your skin and can cause irritation. Be careful around hot objects and hot furnaces.
Tips and warnings
- Make moulds using different waxes for different properties and results.
- Try casting with different plasters to achieve different surface finishes.
- Always wear proper clothing, materials and chemicals can get on your skin and can cause irritation.
- Be careful around hot objects and hot furnaces.